Each day about fifteen new cases of amyotrophic lateral sclerosis (ALS, sometimes called Lou Gehrig's Disease) are diagnosed in the United States. The disease that degenerates the nerves most commonly affects those between 40 and 60 years old.

It is a horrible illness. The patient may ultimately lose their ability to control all voluntary movement except of the eyes.

Scientists have yet to determine what causes ALS but they are closing in on an answer, said Paul Cox, who runs the Institute for Ethnomedicine in Jackson Hole, Wyo.

"We think we are on to something," Cox said in a speech this week at the Beach Club in Palm Beach sponsored by the St. Louis-based Institute for Science and Health.

Cox believes ALS is caused by a common neurotoxin which may act as a trigger for the disease. He also believes it affects those who have genes that make their bodies unable to process the neurotoxin.

Cox, a botanist, studied ALS in the Chamorro people in Guam and have a rate of ALS a hundred times higher than in the United States. He found people who died of ALS ingested a high amount of the neurotoxin as part of their unusual diet.

Because the neurotoxin, known as BMAA, can be tested in people's hair, Cox believes scientists will soon be able to test people for early signs of ALS and eventually find a way to counteract it.

"ALS is the end point of a disease process that goes on for 30 to 40 years before the onset of symptoms," he said.

Cox's research has been published in the National Academy of Sciences' journal Ecology.

If ethnobotanist Paul Alan Cox's theory is right, an ancient bacteria could be a factor in at least some cases of Alzheimer's disease, Lou Gehrig's disease and other neurodegenerative illnesses.

For the time being, that's a big "if," he acknowledged during a presentation last week at The Society of the Four Arts, which was hosted by the Garden Club of Palm Beach.

Cox, former director of the National Tropical Botanical Garden, is head of the Institute for EthnoMedicine, in Jackson Hole, Wyo.

Ethnobotanists search for medical cures by studying patterns of wellness and disease in indigenous populations.

In the mid-1990s, Cox flew to Guam to investigate the diet of tribes in the southwestern village of Umatac. In the early 20th century, scientists noted that members of the Chamorro tribe had experienced symptoms similar to Lou Gehrig's disease — stooped posture, impaired speech, a lack of facial expression, a shuffling walk and resting tremors — at a rate 50 to 100 times higher than that of the general population.

Cox discovered that the tribe makes flour from the seeds of the cycad, a plant that grows in tropical and subtropical locales. The seeds and roots contain BMAA — an amino acid that is toxic in high amounts. BMAA is produced by cyanobacteria — or blue-green algae — that lives in the plant's roots.

The flour itself wasn't enough to cause the condition, but the local flying fox bat consumes large quantities of cycad seeds and thus contains 10,000 times more neurotoxins. Cox learned that the large bat was a favorite meal of the Chamorros before the 1950s, when overhunting resulted in fewer bats to consume.

"These people, when they are eating the bat, are getting a huge dose of neurotoxin," Cox said.

The reduction in the bat population resulted in a subsequent drop in neurodegenerative disease in the village, he said.

Seeking to identify the cause of the degenerative disease, Cox and collaborators studied the brain tissue of some of the deceased villagers and those of a control group of 20 Canadians. All of the Chamorro tissue contained the neurotoxin. To Cox's surprise, so did eight in the control group; those eight had experienced Alzheimer's disease.

Since then, his research team has partnered with the University of Miami, Scotland's University of Dundee and other institutions to determine whether BMAA is definitely a trigger for neurodegenerative diseases. In 2005, UM said initial tests confirmed the presence of the neurotoxin in the brains of people who had Alzheimer's and ALS.

Lower doses of BMAA do not appear to be harmful to most people because they can excrete or metabolize the neurotoxin, Cox said.

"For most of the people in this room, this just wouldn't be a problem," Cox said. "But there might be a very few people who, because of their genetic makeup, cannot metabolize or excrete this amino acid. They accumulate it and these are the people at risk" of neurodegenerative disease.

Some scientists have been skeptical of Cox's hypothesis, saying the conditions similar to those in Guam years ago would be difficult to replicate.